Add support for image input in model resources and enhance related configurations

- Introduce a new `support_image_input` field in model resources, allowing models to indicate support for image input.
- Update the backend models, schemas, and database seed scripts to accommodate the new field.
- Enhance the AssistantConfig and related routes to handle image input capabilities, ensuring proper validation and error handling.
- Modify the frontend components to include toggles for enabling visual understanding and filtering models based on image input support.
- Implement necessary adjustments in the voice preview and pipeline to integrate video stream handling alongside audio functionalities.

backend/services/pipecat/transports.py

@@ -24,21 +24,26 @@ from pipecat.transports.websocket.fastapi import (
 from pipecat.serializers.protobuf import ProtobufFrameSerializer
 
 
-def _base_params() -> dict:
+def _base_params(*, video_in_enabled: bool = False) -> dict:
     """两种 transport 共享的音频参数。"""
     return dict(
         audio_in_enabled=True,
         audio_out_enabled=True,
+        video_in_enabled=video_in_enabled,
         # EndFrame 后默认补 2s 静音(防止收尾被截断)。我们的挂断已等到机器人
         # 说完才触发,这段静音纯属空等,置 0 让结束语播完立即挂断。
         audio_out_end_silence_secs=0,
     )
 
 
-def build_webrtc_transport(connection: SmallWebRTCConnection) -> SmallWebRTCTransport:
+def build_webrtc_transport(
+    connection: SmallWebRTCConnection,
+    *,
+    video_in_enabled: bool = False,
+) -> SmallWebRTCTransport:
     return SmallWebRTCTransport(
         webrtc_connection=connection,
-        params=TransportParams(**_base_params()),
+        params=TransportParams(**_base_params(video_in_enabled=video_in_enabled)),
     )